Here are some words on the benefits of cartridge brass annealing by Bob Blaine of Sinclair International.

The Not-So-Arcane Art of Brass AnnealingA lot of folks hear about annealing brass cartridges cases, and just assume it must be something that’s hard to do. Once you understand what annealing is, why it’s done, and what tools you need to do it, annealing is actually a fairly simple process.

What Is Annealing?

Annealing means heat treating the neck and shoulder of a brass cartridge case to make it softer so it will seal the chamber during firing. Unlike steel, brass gets softer as you heat treat it, not harder. What makes brass cartridges become harder is firing the cases in your gun, and then working them in your reloading dies. Both those operations will cause brass to harden, which leads to splits and cracks in the cases.

Why Do We Anneal Brass?

One reason to anneal your brass is to extend its life, so you can reload it more times. One of the first signs that it’s time to anneal is splitting at the case mouth, or cracks in the neck or shoulders of your brass. Another thing to look out for is if it suddenly takes more pressure, or less pressure, to seat bullets into the cases than it used to. Once symptoms like these appear, many shooters think the brass is no longer usable and discard it. But as long as the primer pockets are still tight, these cartridge cases are still useable - if you anneal them properly.

Another reason to anneal brass cases is if you are reforming them from a larger case to a smaller case, such as in making wildcat cartridges. When you set the shoulder back on the case, the neck walls will thicken from the shoulder’s extra brass, which will harden up as you work it into the new configuration. This area of the worked brass needs to be annealed so that when it is fireformed, it will seal the chamber and properly form out to the new configuration.

No matter why you anneal your cases, the key to proper annealing is to not overheat the cases. When you use a flame to heat the neck and shoulder, make sure that you do not bring the brass to a bright, glowing red color. If the brass reaches a bright, glowing red, you have most likely overheated the case, and it will be unsafe to fire, even if you quickly quench it with water.

How Was Case Annealing Traditionally Done?

Many of us familiar with annealing were taught to fill the brass cases halfway with water, and then place them into a pan of water deep enough for the water level to reach halfway up the outside of the case. The water inside and outside the case acts as a heat sink to protect the base of the case from overheating.

An annealing trick that my father showed me, when I was at the tender age of 10, was to work in a fairly dark area. As I heated the cases, they would start to glow with just enough color that I could just barely see it in the darkened room. Once the case heated up enough for this barely-glowing color to spread evenly around the neck and shoulder, I would tip it over with the torch head so the brass would quench in the water it was standing in. This process left the neck and shoulder of the case softer than the middle and lower portions of the case.

How Is Modern Annealing Different?

Today we have better ways of annealing that are far more consistent than the old-fashioned method that I have just described. One of the best ways is to use the Hornady Annealing System, which we sell as our item number #041220. This kit comes with three different size case holders that will allow you to spin the case while it is in the flame for very uniform heating of the neck and shoulder area.

The Hornady Annealing System also includes a bottle of heat-sensitive paint called Tempilaq. This paint is designed to change color when heated to 475° F (246° C). We usually recommend applying the paint to the inside of the case mouth because the flame will ablate the paint from the outside of the case as it heats. You will be able to see the paint inside the case mouth change color as the brass case rotates, and when this occurs, you will want to let the case fall out of the holder into a pail of cool water to quench. Please keep in mind that you can vary how hot the brass gets by using different Tempilaq formulas that change colors at different temperatures. If you need different Tempilaqs for different temperatures, Brownells sells several versions of it.

There are other types of modern annealing tools, such as ring type annealers that rotate at a set RPM as they move the brass cases through a flame. With these ring-type annealers, the brass will usually be allowed to fall though the bottom of the ring into a container of water at the end of the cycle.

No matter what method you use to anneal your brass, the most important thing to remember is not to overheat the middle and base of the case. Overheating the case makes it unsafe to use.

What Else Do I Need To Know?

After a case has been properly heated and then quenched, it is then ready for the balance of the reloading operations. Here is a quick tech tip for those of you wondering what properly annealed brass should look like when it’s done. Just take a look at a new piece of Lapua brass, if it’s available to you. Lapua always leaves the annealing color on the case so that the reloader can see that the case has been properly annealed. A lot of the other manufacturers will polish this annealing color off to make their brass nice and shiny, but Lapua leaves it on their cases.

As you can see, the annealing process can be quite simple to work with, especially with the proper tools like the Hornady Annealing Kit. The paybacks of extended case life, and the ability to reform cases into different dimensions, more than make up for the initial setup cost of what I consider to be an important tool for precision reloading.

As always, if you have any additional questions, please do not hesitate to call any of us on the Tech Staff here at Sinclair.

When I set up my machine I do it in a fairly dark room as suggested. The dull red is what you want, if sparks fly off of it, you are ruining them. Usually in the last second in the flame, the flame itself will turn red. That is about right. Not getting them hot enough, is a waste as they do not soften, and spring back after sizing, giving inconsistent neck tensions. I heat at the junction of the neck and shoulder, as I am bumping back the shoulders .003-.004.

I go with Corjack on annealing.I just hold the brass in my fingers & heat for around 13-15 secs. until the brass colours & before getting it red hot,then just place on a dry or damp cloth to cool.Quenching doesn't really help at all & simply means you have dry out your cases..tedious job!It works for me doing this around three - four firings.No using tempilaq either, don't need it.

Just anneal as above & f/l resize to fired case headspace dimension.The extension of case life is astonishing, I'm still using thirteen year old brass in my .25-06 and I'm not holding back on MV either.

I used to do annealing on 303 brass necked up to .44 cal to make brass .410 shotgun brass.I would put them in a tray of oil half way up the case and heat them till they just hit red and then let them cool.I don't think it was the best way looking back at it with older eyes, but it seemed to do the trick.

SPEEDY wrote:I got a bag of second hand brass from Aussiegunnut for the 6mmBR that he was even nice enough to anneal for me.No split case necks from the cases I've reloaded 3 times now, out of 200 or so only two had splits after sizing so that's pretty good from retired competition brass.

That's great news Speedy, some of the brass had 20 loading or more on it... I hope you're shooting bug holes with it!

Actually, now I'm looking at loading some 108gn Amax loads and trying it for accuracy.I figured I will be doing less spotlighting, honestly I haven't done much of that in the last 7-8 years so nothing the 308win can't fill in for.I've just put an offer in on a house down in Albury so I will probably do more VIC state forrest hunts and trips away for pigs then spotlighting farms for foxes.

So that 6mmBR is going to be a range day barrel, and that Bix&Andy trigger should help make it a real tack driver.

I have to agree, AMP does do their homework and they have a passion for what they are doing, it shows through in their work. I especially like that they publish contradictory information that shows why earlier work was in error. I'm a physicist by formal education and have looked over many academic papers. Most are loath to admit they made an erroneous finding or are coerced into group think.

Aussiegunnut wrote:That's great news Speedy, some of the brass had 20 loading or more on it... I hope you're shooting bug holes with it!

Actually come to think on it, did that brass come from two different people?I noticed that about 1/3 had a much harder case to full length size, I thought perhaps that was from a rifle that had a more generous chamber and they only neck sized the brass.It might have been different annealing heat but with that machine of yours I doubt that, so that only leaves brass from two different rifles.I just resized 60 empty cases and they all felt exactly the same.

Aussiegunnut wrote:That's great news Speedy, some of the brass had 20 loading or more on it... I hope you're shooting bug holes with it!

Actually come to think on it, did that brass come from two different people?I noticed that about 1/3 had a much harder case to full length size, I thought perhaps that was from a rifle that had a more generous chamber and they only neck sized the brass.It might have been different annealing heat but with that machine of yours I doubt that, so that only leaves brass from two different rifles.I just resized 60 empty cases and they all felt exactly the same.

There's a good chance there's a combination of things going on, but the different chamber dimension from 3 rifles, different batch numbers of brass (there was 6 brand new cases amongst that lot that hadn't even been fired that had split necks - a common issue on certain lots of earlier brass) and the number of firings on each case may have had something to do with it..? As long as your die is sizing the cases properly all should be ok.

Frequent annealing case necks is important particularly when you have a large chamber/die mismatch. I have a 22-250 that I noticed was getting frequent neck splits when resizing even after 2 firings. If you have a good neck or FL resizing die and chamber combination the neck diameter change/descrepancy should be only 4-6 thou maximum whilst realoading. This 22-250 combination using Hornady dies had a 15 thou descrepancy and hence i was overworking the case necks and hence the splitting. I have since changed to Redding competition dies and have the neck bushing 2 thou larger than the diameter of the loaded bullet neck diameter. So neck work on the brass is reduced to a minimum. If you want to see whats going on - try this for starters. Measure the case neck diameter of your loaded bullet. Write that down. Now fire the bullet and measure the neck diameter. Write that down. Now take your reloading die - either neck or FL die and take the expander ball out. Now use the die and then measure the neck diameter once again. Write that down. Now you can subtract the fired cartridge neck diameter from the neck or FL sized ( without the expander ball ) cartridge neck to work out how much neck movement your brass is getting. If it is more than 6 thou you have a manure chamber / die combination and need to anneal your brass frequently or get a better set of dies - the latter preferably. I have a Cheytac 375 where the combination was so good that the descrepancy was only 4 thou. Necks hardly moved and did not harden. I annealed every 3rd load anyway. At $4 per shell you'd want to.

I have a suspicion that Lee thought the .45 Blaser took .452 pistol bullets rather than .458"s and made their dies with this in mind - now you'd expect this to decrease brass life but the grim reality is the cases go thin at the head before the neck splits from overwork Thankfully I only have to get brass shipped from Victoria rather than from Germany